Reducing-valve.



UNITED STATES Patented October 6, 1908.

PATENT OFFICE.

SWENEY MUNSON, OF HASTINGS, NEBRASKA.

. manuelrio-VALVE.

PECFICATION forming' part of LettersPatentNo. 740,898, dated October 6, 1903. K

l Application tiled March 3, 1903. Serial No. 145.896. (No model.)

To all whom it may concern/ Be it known that L SWENEY MUNSON, a citizen ofthe UnitedStates, anda resident of Hastings, in the county of Adams and State of Nebraska, have invented a new and Improved Reducing-Valve, of which the following is a full, cleaigand exact description.

This invention relates to improvements in graduating reducing-valves, more particularly for air-brakes on railway-trains. It is desirable to have an air-brake that will exert its maximum braking power at all speeds without sliding the car-wheels at any time during the slow-up. For instance, a train running at a speed of sixty miles per hour the oar-wheels will stand nearly double the amount of pressure on thebrake-shoeswithout sliding than they wouldrat a speed of twenty miles per hour. Consequently if the pressure canbe reduced at the same ratio the speed is diminishing the desired result is obtained. For illustration, a train running sixty miles per hour requires about thirty seconds to cometo a full stop. Now with a graduating red ucing-valve the train-line pres sure of one hundred pounds can' be carried instead of seventy pounds, which is the maximum pressure allo'wed without a reducingvalve. Seventy pounds `train-line pressure gives about fty pounds brake-cylinder pressure,and one hundred pounds train-line pressure gives about eighty-five pounds brakecylinder pressure.

Therefore the object of my invention is to provide a valve of simple vconstruction for gradually reducing the brake-cylinder pressure from eighty-five pounds to fifty pounds in about twenty seconds, when the fifty pounds pressure remaining in the brake-cylinder willbe maintained until the train comes to a stop or the brake is released voluntarily by the engineer.

I will describe a reducing-valve embodying my invention and'then point out the Vnovel features in the appended claims.

Reference is to be had to the accompanying drawings, forming a part of this specilication, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is a sectional elevation of a red ucing-valve embodying my invention, showing the valve in closed or normal position. Fig.

2 is a similar section, but showing the valve in its full-opened position. Fig. 3 is a plan view of the valve-casing and valve, and Fig. 4 is a perspective view of a strainer employed.

The valve-casing comprises a lower portion 1 and an upper portion 2, removably secured to the lower portion. As here shown, the upper portionhas an interior screw-thread for engaging with an exterior screw-thread of the lower portiomand between these two portions of the valve-casing is a gasket 3, of leather or other suitable material. The attaching of the valve to an air-brake cylinder-head can be done in two ways--as shown in Figs. 1

and 2 by screwing directly into the cylinderhead, as shown bylan exterior thread 4. in Fig. 1, or by screwing it onto the pipe that connects the triple valve to the brake-cylinder by `means of the interior thread 5, as shownin Fig. 2. Y

Arranged within the upper portion of the valve-casing is a hollow strainer 6, and so arranged that all the air coming from the brake-cylinder must pass through the .perforations of said `strainer before entering the chamber 7 of the valvecasing, thereby eX- cluding all dirt that might interfere with the proper working of the piston in said chamber. It is convenient to makethe strainer removable, so that a test-gage may be put in its place to test the resistance of the spring employed for regulating the valve-pressure.v

The valve consists of a piston-like head 8, having a stem, a portion 9 of which is longitudinally tapered and forms the reducing portion of the. valve, as will be hereinafter described. This tapered portion of the valvestem is movable through an opening 10 in the lower-,wall of the portion 1 of the valve-casing, and the extension 11 of the valve-stem projects into a tubular extension 12 of the valve-casing. A nut 13 screws into the lower portion of the tubular extension 12, and on V,this nut is atube 14, which formsa-'guide for the valve-stem. Engaging at one end with the nut 13 and at the other end with a washer 11i on the valve-stem is a regulating-spring 15. The washer 14.a engages with a collar 16 on the stem, and it is obvious that by adjusting the nut 13 in the tubular portion 12 the tension of the spring 15 may be regulated to any desired air-pressure. The nut 13 is pro- IOO vided with a longitudinal slot 17, through which a pin or cotter may be passed to hold the nut as adjusted, the said pin or cotter passing through openings 18 in the tubular extension 12.

Arranged in the wall of the portion 1 of the valve casing are channels 19, forming air passages which at the bottom are designed to communicate with ports 20, formed in a downwardly-extended flange 21 of the valve-head or piston 8, and below the lower Wall of the casing l are exhaust-ports 22, leading to the outer air.

In operation, assuming that the spring is adjusted to withstand a resistance of fifty l pounds pressure on the piston head or valve 8, the air from the brake-cylinder or triple valve enters the graduating reducing-valve and pushes or forces the piston 8 to the bottom of the chamber 7. Then the air passes through the channels 19, the ports 20, through the opening 10, around the stem, and out through the exhaust-ports to the atmosphere. As before mentioned, the tapered portion 9 of the valve-stem is the graduating feature.

l' When the air is first slowly escaping through the opening 10, the spring will slowly force the Valve upward, and as said opening 10 is gradually enlarged on account of the tapering of the stem the Vspring is gradually forcing the piston to its seat against the gasket 3, thus gradually reducing the pressure in the brake-cylinder from eighty-five pounds to fifty pounds in a time limit of, say, about twenty seconds. The time limit can readily be changed by changing the taper of the stem portion 9.

It is obvious that this valve is practically automatic inall its features.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. A reducing-valve, comprising a valve.- casing, a piston-valve movable in said casing, and a tapered stem forsaid piston-valve, movable through an opening in the lower portion of the valve-casing and forming the graduating-valve, substantially as specified.

2. A reducing-valve, comprising a valvecasing, a piston-valve movable in said casing, the said casing having an air-channel in its inner wall, the said piston-valve havinga port in its lower portion, a tapered stem for said piston-valve, movable through au opening in the lower wall ot the'valve-casing, and a spring for moving the valve in one direction, substantially as specified.

3. A reducing graduating-valve, comprising a valve-casing, a piston-valve movable in said casing, a tapered stem for said pistonvalve, movable through an opening in the lower wall of the casing,the said piston-valve having a port or ports in its lower portion to provide communication with said opening and also to provide Vcommunication with a channel or channels formed in the wall of the valve-casing, a spring for moving said valve in one direction, and means for regulating the tension of the spring, substantially as specified. A

4. A reducing.graduating-valve, comprising a valve-casing having' channels in its inner wall and an opening in ,its lower wall communicating with exhaust-ports, a pistonvalve -movable in said casing and having a port or ports in its lower portion, a tapered stem for said piston-valve, movable through the opening in the valve-casing, a spring for moving the valve in one direction, a nut engaging in a tubular extension of the valvecasing and with which one end of said spring engages, and means for locking said nut as adjusted, substantially as specified.

5. A reducing graduating-valve, comprising a valve-casing, a graduating-valve arranged in said casing, and a tubular strainer removably placed in the upper portion of said valve-casing, substantially as specified.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

swENEY MUNsoN.

Witnesses PATRICK NowLAN, WILLIAM E. FLETCHER. 

